Analysis of common defects in zinc alloy die castings

1、 There are patterns on the surface of zinc alloy die castings and traces of metal flow

1. The runner to the casting inlet is too shallow.

2. When the injection pressure is too high, the velocity of metal is too high and the liquid metal splashes.

Adjustment method:

1. Deepen the gate runner.

2. Reduce the injection specific pressure.

2、 There are small bumps on the surface of zinc alloy die castings

1. The surface is rough.

2. There are scratches, pits and cracks on the surface of die cavity.

Adjustment method:

1. Polishing cavity.

2. Replace the cavity or repair.

3、 There are push rod marks on the surface of the casting, and the surface is not smooth and rough

1. The ejector rod (ejector rod) is too long;

2. The surface of the cavity is rough or there are impurities.

Adjustment method:

1. Adjust the pusher rod length.

2. Polish the cavity, remove impurities and oil.

4、 The causes of cracks or local deformation on the surface of zinc alloy die castings are as follows:

1. Uneven distribution or insufficient quantity of ejector rods and uneven stress:

2. The fixed plate of pusher bar is inclined when it is working, resulting in large force on one side and small force on the other side, resulting in product deformation and cracks.

3. The wall of casting is too thin and deformed after shrinkage.

Adjustment method:

1. Increase the number of ejector rods and adjust their distribution position to make the casting ejection force balanced.

2. Adjust and re install the push rod fixing plate.